The toxicity of ZnO and CuO nanoparticles on biological wastewater treatment and its detoxification: a review / 生物工程学报

The wide use of ZnO and CuO nanoparticles in research, medicine, industry, and other fields has raised concerns about their biosafety. It is therefore unavoidable to be discharged into the sewage treatment system. Due to the unique physical and chemical properties of ZnO NPs and CuO NPs, it may be toxic to the members of the microbial community and their growth and metabolism, which in turn affects the stable operation of sewage nitrogen removal. This study summarizes the toxicity mechanism of two typical metal oxide nanoparticles (ZnO NPs and CuO NPs) to nitrogen removal microorganisms in sewage treatment systems. Furthermore, the factors affecting the cytotoxicity of metal oxide nanoparticles (MONPs) are summarized. This review aims to provide a theoretical basis and support for the future mitigating and emergent treatment of the adverse effects of nanoparticles on sewage treatment systems.

Impact of Metal and Metal Oxide Nanoparticles on Male Reproductive System: A Comprehensive Review

Technological advancements and increased use of chemically hazardous materials have become a concern for human health. Environmental pollutants such as engineered metal and metal oxide nanoparticles (M&MONPs) are reported to contribute to significant health-related problems, particularly reproductive health. Reduction in male individuals' reproductive potential is one of the important causes of concern. Literature suggests that exposure to M&MONPs considerably impacts alteration in male reproductive parameters. Therefore, it is required to analyze and understand their effects on male reproductive toxicity. Oxidative stress and changes in redox equilibrium are the significant factors via M&MONPs induce changes in sperm parameters or the reproductive system. Act as endocrine disruptors and interfere with the secretion and function of reproductive hormones such as testosterone and LH, affecting spermatogenesis. Likewise, M&MONPs accumulate in organs as they can pass through the blood-testis barrier, affect Sertoli and Leydig cells, and cause reproductive dysfunction. In this review, we have analyzed the effects of M&MONPs on the male reproductive system and the underlying mechanism of action

ZnO: SnO2 nanocomposite efficacy for gas sensing and microbial applications

The unique characteristics of 2-dimensional hetero structure offers efficient gas sensing with high selectivity to identify gases from the interference gases which is quite difficult. In the present work, ZnO: SnO2Nano composite clusters (NCC) is prepared. A resistive metal oxide volatile organic compound (VOC) gas sensor is fabricated with nullifying the effect of humidity by increasing temperature optimally. A single-step SOL-GEL (SG) synthesis is used to prepare ZnO: SnO2 NCC with maximum Zn/Sn molar concentration ratio of 3. The morphological studies through Scanning Electron Microscopy (SEM), electrical properties due to oxygen vacancies and energy band variations of Nanocomposite are measured. The enhancement of gas sensor sensitivity due to highly mesoporous nature of the composite is observed. From the findings, the abundant mesopores in the range of 2 nm-14 nm and specific surface area of 54.2 m2 g?1 with the average crystal size of 14.236 nm, and polar surface area of the composite 25.9651Åis achieved. When compared to bare ZnO and SnO2 gas sensors, the present gas sensor offers the higher selectivity with enhanced performance due to the mesoporous structure. Fast repeatability rate of 2200 sec at 350?C to ethanol is attained and the overall selectivity of the sensor increased twice as 2.085. The NCC compound is tested firstly with micro organisms such as B. subtilis (B. S), Bacillus cereus (B. C), B. coagulans (B. C), Pseudonymous auriginosa (P. A) are considered for antimicrobial activity. From the findings, zinc stannate compound showed good efficacy towards B. cereus Gram positive and P.A gram-negative. A bacterial growth is arrested highly with B. cereus.

Research progress on electrode technology for dental plaque pH detection / 口腔疾病防治

@#Plaque pH detection technology can detect the risk of caries and assist in the prevention of caries, with a mature theory and a relatively simple operation. With the increasing demand for clinical caries risk detection technology and the rapid development of microelectrode techniques, there is an increasing variety of types of microelectrodes that can detect the pH of dental plaque, including glass microelectrodes, metal oxide microelectrodes and ion-sensitive field effect transistors. The glass microelectrode was the first microelectrode to be applied in this field, but its structure is weak. Among the various options, the iridium oxide microelectrode has become the most promising caries risk detection electrode in recent years because of its high strength and excellent response. Metal oxide microelectrodes can also effectively compensate for the insufficient strength of glass microelectrodes. With advances in electrode technology, miniaturized, sensitive ion-sensitive field effect transistors have attracted the attention of researchers. Scientists have also recently developed a way to detect the pH of dental plaque with an optical no-contact technique. Optical contactless detection technology will not damage the dental plaque structure, so it has great research and clinical prospects. Future research will further improve the strength and performance of these electrodes on the premise of ensuring miniaturization and achieving noncontact detection.

Progress in the application of metal and metal oxide nanoparticles in the antibacterial modification of dental materials / 口腔疾病防治

@#The colonization of microorganisms planted on the surface of teeth and restoration materials is the main cause of oral disease and treatment failure. How to improve the antibacterial properties of dental materials is a hot topic in dentistry. Nano-sized antibacterial materials have attracted much attention. Among them, metal and metal oxide nanoparticles are prominent due to their strong and broad-spectrum antibacterial activity. Thus, in recent years, many studies have used metal and metal oxide nanoparticles to develop antimicrobial dental materials for resin restoration, root canal therapy, orthodontic treatment, and implant surface and removable denture repair and have found that the antibacterial properties of nano-sized materials are significantly enhanced. However, the mechanical properties and esthetic properties of the modified materials are affected, so it is still necessary to explore appropriate modification methods. In addition, most of the experiments are carried out in vitro, which cannot accurately simulate the oral environment. Therefore, the antibacterial effect, cytotoxicity and immune response of these materials in vivo still need further research and exploration. This paper reviewed the potential antibacterial mechanisms and the safety of those nanoparticles and their applications in dentistry.

Advance in research of biodegradable mesoporous silica nanoparticles / 药学学报

Mesoporous silica nanoparticles (MSNs) have been widely used as drug carriers in the diagnosis and treatment of diseases due to their specific characteristics, which include a large surface area, ordered mesoporous structures, easy surface modification and feasible sustained release action for encapsulated drugs. With the research development of MSNs, the biodegradability and removability of mesoporous silica nanomaterials have attracted considerable attention in the clinical application of the MSNs-based formulations. This paper was prepared to emphasize the preparation approaches of biodegradable mesoporous silica nanoparticles through the metal oxide doping method and the organic compound doping method. We discussed the biodegradable mechanism and process of such nanoparticles, and finally, provided an insightful and helpful review of the prospective application of the biodegradable mesoporous silica nanoparticles in medical field.

Molecularly Imprinted Polymer Electrochemical Sensor Based on Fe3O4/MnO2 Doped Graphene Composites for Determination of 17β-Estradiol in Aquatic Environment / 分析化学

In this paper, Fe3O4/MnO2doped graphene molecularly imprinted hybrid material ( Fe3O4/MnO2-MIP@ RGO ) was successfully synthesized via reversible addition fragmentation chain transfer ( RAFT ) molecularly imprinting technique by using methacrylic acid as functional monomer, divinylbenzene as cross-linker, Fe3O4/MnO2@ RGO as carrier, and 17β-estradiol ( 17β-E2 ) as template molecule. A novel molecularly imprinting electrochemical sensor by using Fe3O4/MnO2-MIP@ RGO modified electrode was constructed to specifically detect trace 17β-E2 in water. The experimental results showed that the Fe3O4/MnO2-MIP@ RGO electrochemical sensor exhibited rapid and linear current response to 17β-E2 in water samples with a linear range of 4 nmol/L to 0. 8 μmol/L ( R=0. 9852) , the detection limit was 47. 2 pmol/L (3σ) and the relative standard deviation (RSD) was from 2. 1% to 2. 5% . This study provides a simple and efficient, economical and reliable method for the monitoring of 17β-estradiol in the complex water environment.

Displacers improve the selectivity of phosphopeptide enrichment by metal oxide affinity chromatography / Uso de desplazadores para mejorar la selectividad de los fosfopéptidos enriquecidos por cromatografía de afinidad con óxidos de metales

Abstract: Background: A key process in cell regulation is protein phosphorylation, which is catalyzed by protein kinases and phosphatases. However, phosphoproteomics studies are difficult because of the complexity of protein phosphorylation and the number of phosphorylation sites. Methods: We describe an efficient approach analyzing phosphopeptides in single, separated protein by two-dimensional gel electrophoresis. In this method, a titanium oxide (TiO2)-packed NuTip is used as a phosphopeptide trap, together with displacers as lactic acid in the loading buffer to increase the efficiency of the interaction between TiO2 and phosphorylated peptides. Results: The results were obtained from the comparison of mass spectra of proteolytic peptides of proteins with a matrix-assisted laser desorption-ionization-time of flight (MALDI-TOF) instrument. Conclusions: This method has been applied to identifying phosphoproteins involved in the symbiosis Rhizobium etli-Phaseolus vulgaris.

Resumen: Introducción: Un proceso clave en la regulación celular es la fosforilación de proteínas, que se lleva a cabo por cinasas y fosfatasas. Sin embargo, los estudios de fosfoproteómica son difíciles debido a la complejidad de la fosforilación proteica y el número de sitios de fosforilación. Métodos: En el presente trabajo se describe una eficiente estrategia metodológica para analizar fosfopéptidos de proteínas separadas mediante electroforesis bidimensional. En este método, una columna con microesferas de dióxido de titanio (TiO2/NuTip) se utilizó para atrapar los fosfopéptidos en la superficie del TiO2 previamente empacado en una punta. El uso de desplazadores en el buffer de carga, como el ácido láctico, mejoró significativamente la selectividad. Resultados: Los resultados se obtuvieron mediante la comparación de los espectros de masas de péptidos proteolíticos de proteínas analizados utilizando un instrumento de desorción/ionización láser asistida por matriz-tiempo de vuelo (MALDI-TOF). Conclusiones: Este método se ha aplicado para la identificación de fosfoproteínas involucradas en la simbiosis del Rhizobium etli con Phaseolus vulgaris.

Nanoparticle-based drug delivery systems: promising approaches against infections

Despite the fact that many new drugs and technologies have been developed to combat the infectious diseases, these have continued to be global health challenges. The use of conventional antimicrobial agents against these infections is always associated with problems such as the development of multiple drug resistance and adverse side effects. In addition, the inefficient traditional drug delivery system results in inadequate therapeutic index, low bioavailability of drugs and many other limitations. In this regard, antimicrobial nanoparticles and nanosized drug delivery carriers have emerged as potent effective agents against the infections. Nanoparticles have unique properties owing to their ultra small and controllable size such as high surface area, enhanced reactivity, and functionalizable structure. This review focused on different classes of antimicrobial nanoparticles, including metal, metal oxide and others along with their mechanism of action and their potential use against the infections. The review also focused on the development of nanoparticle systems for antimicrobial drug delivery and use of these systems for delivery of various antimicrobial agents, giving an overview about modern nanoparticle based therapeutic strategies against the infections.

Influence of various metal oxides on mechanical and physical properties of heat-cured polymethyl methacrylate denture base resins

PURPOSE: To evaluate the effect of various metal oxides on impact strength (IS), fracture toughness (FT), water sorption (WSP) and solubility (WSL) of heat-cured acrylic resin. MATERIALS AND METHODS: Fifty acrylic resin specimens were fabricated for each test and divided into five groups. Group 1 was the control group and Group 2, 3, 4 and 5 (test groups) included a mixture of 1% TiO2 and 1% ZrO2, 2% Al2O3, 2% TiO2, and 2% ZrO2 by volume, respectively. Rectangular unnotched specimens (50 mm x 6.0 mm x 4.0 mm) were fabricated and droptower impact testing machine was used to determine IS. For FT, compact test specimens were fabricated and tests were done with a universal testing machine with a cross-head speed of 5 mm/min. For WSP and WSL, discshaped specimens were fabricated and tests were performed in accordance to ISO 1567. ANOVA and Kruskal-Wallis tests were used for statistical analyses. RESULTS: IS and FT values were significantly higher and WSP and WSL values were significantly lower in test groups than in control group (P<.05). Group 5 had significantly higher IS and FT values and significantly lower WSP values than other groups (P<.05) and provided 40% and 30% increase in IS and FT, respectively, compared to control group. Significantly lower WSL values were detected for Group 2 and 5 (P<.05). CONCLUSION: Modification of heat-cured acrylic resin with metal oxides, especially with ZrO2, may be useful in preventing denture fractures and undesirable physical changes resulting from oral fluids clinically.

Effects of selected metal oxide nanoparticles on multiple biomarkers in Carassius auratus / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the biological effects of nanoscale copper oxide (nCuO), zinc oxide (nZnO), cerium dioxide (nCeO2) and their mixtures on Carassius auratus.</p><p><b>METHODS</b>Juvenile fish (Carassius auratus) were exposed to aqueous suspensions of nCuO, nZnO, and nCeO2 (alone and in mixtures) at concentrations of 20, 40, 80, 160, and 320 mg/L. The biomarkers-acetylcholinesterase (AChE) in brain, sodium/potassium-activated ATPase (Na+/K+-ATPase) in gill, and superoxide dismutase (SOD) and catalase (CAT) in liver-were determined after 4 days of exposure. Integrated biomarker response (IBR) was calculated by combining multiple biomarkers into a single value.</p><p><b>RESULTS</b>AChE and SOD activities were significantly inhibited by all test metal oxide nanoparticles (NPs) at high concentrations (⋝160 mg/L) with the exception of nCeO2. Na+/K+-ATPase induction exhibited bell-shaped concentration-response curves. CAT activity was significantly inhibited at concentrations equal to or higher than 160 mg/L. The order of IBR values was nCeO2 ≈ nZnO/nCeO2 ≈ nCuO/nCeO2 < nCuO/nZnO/nCeO2 < nZnO < nCuO < nCuO/nZnO. The joint effect seemed to be synergistic for nCuO/nZnO mixtures, additive for the ternary mixture and less than additive or antagonistic for the binary mixtures containing nCeO2.</p><p><b>CONCLUSION</b>Concentration-dependent changes of enzymatic activities (AChE, Na+/K+-ATPase, SOD, and CAT) were observed in fish exposed to nanoscale metal oxides. IBR analysis allowed good discrimination between the different exposures and might be a useful tool for the quantification of integrated negative effects induced by NPs toward fish.</p>

In vivo measurement of radiation dose during radiotherapy in breast cancer patients using MOSFET dosimeter / 中华放射肿瘤学杂志

ObjectiveThe purpose of the study was to observe and analysis the actual dosage of patients with breast cancer using metal oxide semiconductor field effect transistor (MOSFET) detector.MethodsFirst, Phantom measurements were performed to investigate dose distribution in the area of the junction in a half-field matching method and the influence of factors related to the accelerator. In vivo dose measurements were performed for patients with breast cancer to investigate the skin dose and the junction of supraclavicular-axillary field and tangential field in 6 MV X-ray beams. ResultsPhantom measurements showed that the relative deviation in the junction were within + 3％, and the dose distributions in the junction area depended on the matching field direction (x or y). In vivo measurement of tangential region for patients showed that, the maximum dose deviation between measurement and calculation was -30. 39％,the minimum deviation was - 18. 85％, the average dose deviation was -24. 76％. The dose deviation of tangential fields for patients with breast-conserving surgery was larger than that patients with radical surgery (t =2. 40 ,P＜0. 05), while dose deviation of supraclavicular-axillary fields was not significantly different. The average values of 15 fraction in the junction area showed more stable than one individual measurement.ConclusionsIt is important to real-time, in vivo measurement of radiation dose during radiotherapy in patients with breast cancer, and change treatment plan in time, to ensure the accuracy of target dose.

Micro Potentiometric Label-free Immunosensor for Glycated Hemoglobin / 分析化学

A miniaturized potentiometric label-free immunosensor based on the standard complementary metal-oxide-semiconduction transistor(CMOS) process and micro fabrication technique was developed to monitoring diabetes, which could detect the concentrations of glycated hemoglobin (HbA1c) and hemoglobin. This immunosensor includes a micro field-effect transistor based sensor chip integrated with signal readout circuit and a disposable probe electrode. The micro sensor chip was designed by our lab and fabricated by Chartered Semiconductor, Singapore. The disposable probe electrode, which was integrated with sensitive electrodes array and micro reaction pool, was deposited on polyester plastic based on micro fabrication techniques. Antibody of HbA1c and hemoglobin were immobilized on the electrode based on self assemble monolayer and gold nanoparticles. The characteristics of the electrode during modification were studied by cyclic voltammetry and electrochemical impedance technique. The response characteristic of the immunosensor was detected. HbA1c from 4 to 24 mg/L and hemoglobin from 60 to 180 mg/L can be detected by this immunosensor.